Sufficient cargo tanks shall be（）prior to each ballast voyage in order that，taking into account the tanker’s trading pattern and expected weather conditions，ballast water is put only into cargo tanks which have been crude oil washed.

A.a yarn core
B.no core
C.three strands
D.12 threads

A.marline or ratline wound along the grooves of a rope
B.narrow strips of light canvas or cotton cloth spiral-wrapped along the rope
C.marline tightly wound on the rope by means of a board or mallet
D.a splice made by laying the strand of one rope into the vacated grooves of another rope

A.chockablocking
B.fleeting
C.overhauling
D.two blocking